The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 1977
Filed:
Feb. 20, 1975
Lester R Querry, Laurel, MD (US);
Rixon, Inc., Silver Spring, MD (US);
Abstract
A phase-locked demodulator for demodulating a phase-difference modulated carrier having a repeated phase offset increment introduced therein. The demodulator includes, in common with conventional phase locked demodulators, a mixer having a first input connected to receive the modulated carrier and a reference carrier generator such as a voltage controlled oscillator (VCO) connected in a phase-locked feedback loop forming the second input to the mixer. In order to reduce the number of output levels, the VCO is tuned to a frequency Fr=Fc.+-.Fb[(.alpha.)/360] where Fc is the carrier frequency, Fb is the baud rate and .alpha. is the repeated phase offset. In this way the phase offset increment introduced into the modulated carrier is substantially cancelled out thereby leaving only the phase changes containing data information.